Chloro and nitro containing phenyl phosphites



United States Patent 3,463,838 CHLORO AND NITRO CONTAINING PHENYL PHOSPHITES Jack Hensel, Fairway, Kans., and Delta W. Gier, Parkville, Mo., assignors to Chemagro Corporation, New York, N.Y., a corporation of New York No Drawing. Original application Dec. 9, 1965, Ser. No. 512,778, now Patent No. 3,416,911, dated Dec. 17, 1968. Divided and this application Feb. 14, 1968, Ser. No. 724,306

Int. Cl. C07f 9/12; Atlln 9/36 US. Cl. 260-954 Claims ABSTRACT OF THE DISCLOSURE Phosphites and phosphates are prepared having the formula For 0111 (N02)m a L. 2)p 3 where n is an integer from 0 to 3 and m and p are integers from 1 to 2. The compounds are useful for defoliating and desiccating plants.

This application is a division of my copending application, Ser. No. 512,778, filed Dec. 9, 1965 now US. Patent 3,416,911.

This invention relates to desiccants and defoliants.

Pentachlorophenol is a known cotton desiccant but it does not have government approval. Due to its strongly acidic nature it is quite corrosive in nature.

It is an object of the present invention to prepare novel chloronitro phenyl phosphates.

Another object is to develop a novel process for desiccating and/or defoliating plants, e.g. cotton.

An additional object is to develop cotton defoliants with low toxicities and a low order of corrosiveness.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, While indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications Within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

. Some of the advantages of defoliating plants such as cotton are set forth in Regel Patent No. 3,193,372 on col. 2, lines 3556.

According to the present invention there are used as defoliants and desiccants for cotton and other plants certain phosphites and phosphates.

The phosphites have the formula 0111 (N O2)m a where n is an integer of 0 to 3 when m is 1 or 2 and n is 3 when m is 0 and m is an integer from 0 to 3. Preferably the compounds have at least one nitro group as well as at least one chloro group. The preferred phosphites are tris (trichloromononitrophenyl) phosphites, most preferably tris (2,4,5-trichloro-6-nitro-phenyl) phosphite. The next most preferred compound is tris (2-chloro-4-nitrophenyl) phosphite.

3,463,838 Patented Aug. 26, 1969 ice Phosphites having the formula Clq (NHDm a 0111 (N099 a where n is an integer of O to 3 and p is an integer of 1 to 2.

In general the phosphites are preferred to the corresponding phosphates.

The phosphites and phosphates employed as defoliants and desiccants in the present invention are economical to prepare, noncorrosive and relatively nontoxic.

They are much more economical to prepare, for example than the corresponding monothiophosphates wherein the thio atom is doubly bonded to the phosphorus atom. In addition, the phosphites and phosphates in general are superior defoliants and desiccants to the corresponding monothiophosphates.

Many of the phosphites employed in the present invention are novel compounds and some of the phosphates are also novel compounds.

Examples of compounds which can be used as defoliants and desiccants according to the invention are tris (2,4,5-trichlorophenyl) phosphite, tris (2,4-dichloro-6- nitrophenyl) phosphite, tris (2,4,5-trichloro-6-nitrophenyl) phosphite, tris (2-chloro-4-nitrophenyl) phosphite, tris (2,6-dichloro-4-nitrophenyl) phosphite, tris (2- nitro-4chlorophenyl) phosphite, tris (3-chloro-4-nitrophenyl) phosphite, tris (2,6-dinitro-4-chlorophenyl) phosphite, tris (4-nitrophenyl) phosphite, bis (2,4,5-trichloro-6-nitrophenyl) phosphite, 2,6-dichloro 4 nitrophenyl phosphite, tris (2,4,6-trichloro-3-nitrophenyl) phosphite, tris (2,4-dichloro-6-nitropheny1) phosphate, tris (2,4,S-trichloro-6-nitrophenyl) phosphate, tris (2-chloro- 4-nitrophenyl) phosphate, tris (2,6-dichloro 4 nitrophenyl) phosphate, tris (2-nitro-4-chlorophenyl) phosphate, tris (3-chloro-4-nitrophenyl) phosphate, tris (2,6- dinitro-4-chlorophenyl) phosphate, tris (4-nitr0phenyl) phosphate.

The compounds employed as defoliants and desiccants in the present invention are prepared by reacting one mole of phosphorus trichloride (in preparing the phosphites) or one mole of phosphorus oxychloride (in preparing the phosphates) with 3 moles of the appropriate substituted phenol, e.g. 2,4,5-trichlorophenol, 2,4-dichloro-6-nitrophenol, 2,4,5-trichloro--nitrophenol, 2-chloro-4nitrophenol, 2,6-dichloro-4-nitrophenol, 2-nitro-4-chlorophenol, 3-chloro-4-nitrophenol, 2,6-dinitro-4-chlorophenol, 4-nitrophenol, 2,4,6-trichloro-3-nitrophenol.

The compositions employed in the present invention comprise the active defoliant or desiccant described herein together with materials referred to in the art as adjuvants, diluents, carriers and the like. The thus diluted active ingredient is hereby rendered adaptable for application by means of jets, nozzles, Spreaders, dusters, foggers and similar devices used in the practice of the art. Typical adjuvants, carriers and diluents are represented by water, heavy mineral oil, heptane, benzene, kerosene, xylene, carbon tetrachloride, talc, pyrophyllite, and diatomaceous earth. With water as the diluent it is conventional to add wetting agents to effect good foliage coverage. Among suitable wetting agents are Triton X-lOOI (an alkyl aryl polyester alcohol made by condensing 1 mole of p-octylphenol with 10 moles of ethylene oxide), Triton X-171 (blend of octylphenylpolyethylene glycol adduct having about 16 ethylene oxide units admixed with higher alkyl sulfates having 10-18 carbon atoms in the alkyl group),

were insoluble in ether. For the ether soluble products, the ether filtrate was washed twice with water and dried. The solvent was removed on a spin evaporator at room temperature, and the product again dried under vacuum.

For the ether insoluble products, the residue was trans- 5 Triton X-161 (blend of octylphenyl-polyethylene glycol ferred to a beaker, washed well with cold water and filadduct having between and ethylene oxide units adtered. The wet product was dried in a vacuum desiccator. mixed with higher alkyl sulfates having 10-18 carbon Examples of tris substituted phenyl phosphites having atoms in the alkyl group), Tween 20 (polyoxyalkylene dethe formula (RO) P prepared according to the above rivative of sorbitan monolaurate), glycerol sorbitan 10 described reaction are given in Table 1 while examples laurate, sodium dodecylbenzene sulfonate, sodium steaof the corresponding phosphates having the formula rate, potassuim oleate, sodium lauryl sulfate, sodium do- (RO) P=O are given in Table 2.

TABLE 1 Percent Physical Percent Percent R (in (RO)3 P) Ether solubility Yield condition M.P., C. or P 2,4-diohlorophenyl Soluble 90 Whitepowder 78-80 41.0 5.8 2,4,5-triehlorophenyl d (1 114-116 52. 2 4. 7 2,4-diehloro-6-nitrophenyl 101-103 33. 2 4. 4 2,4,5-triohloro-6-nitrophenyl 78-80 41. 9 4. 1 2-chloro-4-nitrophenyl 117-118 19. 7 5. 5 2,6-dichloro-4-nitrophen (1 113-115 33. 3 4. 6 2-nitro-4-chlorophenyl Yellow crystal. 92-94 18. 4 5. 4 3-ehloro-4-nitropheuyl. 82 Whitepowder 119-120 19.4 5.6 2,6-diuitro-4-ohlorophenyl. 90 Orange solid 73-76 15.3 4.4 4-riitrophenyl ..do 90 Whitep0wder 110-112 6.9

TABLE 2 Percent Physical Percent Percent R (in (RO)3 P) Ether solubility Yield condition M.P., C C P 2,4-dichlorophenyl 86 White powder 100-101 40.1 5.8 2,4,5-triehlorophenyl 90 do 170-172 51.1 4.9 2,4-dichloro-fi-uitrophenyh 90 do. 99-100 32. 5 4.3 2,4,5-triohloro-6-niti'ophenyl 80 Red oil 68-70 41.4 4.0 -chloroi-nitrophenyl 86 Tau powder. 132-133 18.6 5.4 2,fi-dicliloro-4-nitrophenyl 1 0 ..do 212-213 31.0 4.3 2-nitro-4-chlor0phenyL-- 53 Yellow erystal 92-95 18.9 5.6 3-chloro-4-nitrophenyL. 81 White powder.. 142-143 18.4 5.6 2,6-dinitro-4-chlo1ophenyl. 98 Tan solid 70-80 15.8 4.2 4-nitrophenyl 94 White powder"... 158-160 0.7

decane sufonate, sodium lignin sulfonate, tert, dodecyl EXAMPLE 2 polyethylene glycol thioether, long chain ethylene oxidepropylene oxide condensation product.

The emulsifying or wetting agents are generally employed in only very small concentrations, for example, in a quantity up to about 0.3% by weight based on the weight of the emulsion. However, higher concentrations may be used, as high as 5% by weight, provided that it does not exert an adverse effect on the plant preventing defoliation by causing phytotoxicity. When the active ingredient is formulated in oils such formulations can be applied directly to the plant to be defoliated with or without the addition of wetting agents.

The defoliants of the present invention are effective when applied in the range between 0.25 and 10 pounds per acre. The concentration of the active ingredient in the formulations can be varied over Wide ranges depending upon the diluents and the mode of application. Suspensions containing as little as 0.1% by weight can be effectively employed as well as concentrations as high as 5%.

Unless otherwise indicated all parts and percentages are byweight.

EXAMPLE 1 The phosphites and phosphates were all prepared in the following manner. There was employed a 500 m1. threenecked flask equipped with a mechanical stirrer, a reflux condenser, and an addition funnel. The flask was charged with 0.15 mole of the appropriate substituted phenol and 150 ml. of anhydrous ether. Exactly 0.05 mole of phosphorus trichloride (in making the phosphites) or 0.05 mole of phosphorus oxychloride (in making the phosphates) was added cautiously with stirring. Then 0.155 mole (a slight excess) of triethylamine in ml. of anhydrous ether was added dropwise to the reaction mixture with vigorous stirring and intermittent ice cooling. Following addition of the triethylamine, the mixture was heated to ether reflux temperature for four hours.

The slurry was cooled, filtered and washed with ether. Some of the products were other soluble, while others The compounds set forth in Tables 1 and 2 were all tested as cotton defoliants and desiccants in the following formulation. A mixture was made of 1 pound of the phosphite or phosphate being tested in a gallon of Formula A. Formula A was a mixture of 2 parts of a premix and 1 part of dimethylformamide. The premix was composed of 8 parts of xylene (Velsicol AR-50), 1 part of Triton X-l6l and 1 part of butyl Carbitol acetate.

The compounds in the above formulations were then applied to mature cotton at the indicated rates per acre of ingredient to be tested (the phosphite or phosphate). The percentage of defoliation was measured after 4 days as was the percentage of desiccation. The foliation was recorded at both 8 and 2 lbs/acre of ingredient tested while the desiccation was recorded as a combined average amount of desiccation for the two rates by adding the amount of desiccation at 8 lbs/acre to the amount of desiccation at 2 lbs/acre and dividing by two.

The results obtained with tris substituted phenyl phosphites having the formula (RO) P are given in Table 3 and the results with the corresponding phosphates having the formula (RO) P=O are given in Table 4.

TABLE 4- R in (RO)3P=O) fi L232; degiii t igli desll clt tigrl 2,4-dichlorophenyl 2; (2) 0 2,4,5triehlorophenyl 8 0 0 2,4-dich1oro-6nitropheny1 g (i): 80 2,4,S-trichloro-flnitrophenyl.. 3 i8 75 2'chloro--nitrophenyl 3 1g 40 2,(i-dichloro-4-nitrophenyl. g 35 2-nitro-4-ehlorophenyl g 15 B-chloro-mitrophenyl g 2 2,fi-dinitro-kchlorophenyl. a; 4O 4-nitrophenyl g g 0 From Tables 3 and 4 it will be observed that in general the phosphites were superior to the phosphates in combined defoliation and desiccation properties. It will also be observed that both tris (2,4-dichlorophenyl) phosphite and tris (2,4-dichloropheny1) phosphate were ineffective as either defoliationts or as desiccants. Tris (2,4,5-trichlorophenyl) phosphate was ineffective as either a defoliant or as a desiccant but the corresponding tris (2,4,5- trichlorophenyl) phosphite was a moderately good desiccant although inefiective as a defoliant.

Tris (4-nitrophenyl) phosphite was a good defoliant and desiccant while the corresponding tris (4-nitrophenyl) phosphate was a poor defoliant and ineffective as a desiccant.

The best compounds in overall defoliation and desiccant properties were tris (2,4,5-trichloro-6nitrophenyl) phosphite and tris (2,G-dichloro-4-nitrophenyl) phosphite while the two compounds showing the best desiccant properties were tris (2,4,S-trichloro-6-nitrophenyl) phosphate and tris (2-chloro-4-nitrophenyl) phosphite.

EXAMPLE 3 In another experiment tris (2,4,5-trichloro-6-nitrophenyl) phosphite in actual field tests in four geographical locations gave desiccation of mature cotton plants at 4.0, 3.0, 2.0 and 1.5 pounds of active ingredient per acre.

We claim:

1. A phosphite having the formula o P XX References Cited UNITED STATES PATENTS 3,231,359 l/l966 Newallis et al. 260-954 XR CHARLES B. PARKER, Primary Examiner ANTON H. SUTTO, Assistant Examiner US. Cl. X.R. 

